1. Field of the Invention
This invention relates to an image forming apparatus, a communication controlling method and a storage medium, and particularly to an image forming apparatus, a communication controlling method and a storage medium suitable for application to an electrophotographic recording apparatus, an electrostatic recording apparatus or the like having expendibles such as toner cartridges or interchangeable parts such as devices to be interchanged due to their service lives.
This invention relates to an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus having expendibles such as toner cartridges or interchangeable parts such as devices to be interchanged due to their service lives.
2. Related Background Art
There have heretofore been image forming apparatus for forming an image on paper by the electrophotographic recording process or the like. FIG. 13 of the accompanying drawings schematically shows the construction of an example of an image forming apparatus of the tandem type. In the following description, a plurality of functionally equal units exist in the image forming apparatus and therefore, reference numerals designating the plurality of functionally equal units are given suffixes a, b, c and d, and in descriptions common to all units, those reference numerals will sometimes be shown with the suffixes a, b, c and d omitted therefrom.
The image forming apparatus of the tandem type is comprised of a plurality of image forming portions including black (Bk), yellow (Y), magenta (M) and cyan (C). In each image forming portion, the reference numeral 18 designates a photosensitive drum (image bearing body) made of an organic photosensitive body or an amorphous silicon photosensitive body, and the photosensitive drum 18 is subjected to the uniform charging process of predetermined polarity and potential by a charging device 16 such as a charging roller in the rotating process thereof. A scanner unit 11 outputs a laser beam 13 modulated correspondingly to an image signal of desired image information from an image signal generating unit such as an image reading apparatus, not shown, and scans it on the photosensitive drum 18 by a deflecting mirror, not shown, through an optical lens system, not shown, whereby an electrostatic latent image is formed on the surface of the photosensitive drum.
FIG. 14 of the accompanying drawings is a perspective view showing the construction of the scanner unit 11 of each image forming portion of the above-described image forming apparatus. The operation of the scanner unit 11 will hereinafter be described with reference to FIG. 14. The reference numeral 31 denotes a semiconductor laser, the reference numeral 32 designates a collimator lens, the reference numeral 33 denotes a cylindrical lens, the reference numeral 34 designates a polygon mirror, the reference numeral 35 denotes a scanner motor, the reference numeral 36 designates a spherical lens, the reference numeral 37 denotes an fxcex8 lens, the reference numeral 38 designates a deflecting mirror, and the reference numeral 39 denotes a horizontal synchronizing signal detector.
The semiconductor laser 31 emits light by a laser driving signal modulated on the basis of the image signal, and the laser beam is shaped into a beam shape by the collimator lens 32 and the cylindrical lens 33. The polygon mirror 34 is rotated by the steadily rotating scanner motor 35, and the laser beam reflected by the surface of the polygon mirror is scanned in a fan-shape. Further, the laser beam is shaped by optical lens units such as the spherical lens 36, the fxcex8 lens 37 and the deflecting mirror 38 and also scans the surface of the photosensitive drum at constant velocity. The horizontal synchronizing signal detector 39 is generally comprised of a photodiode and an amplifier, and detects the scanned laser beam and generates a synchronizing signal in a main scanning direction.
Further, FIG. 13 will be described. The reference numeral 14 designates a developing device which contains a developer (toner) therein and has a toner carrying mechanism generally directed to the charging and carrying of the toner. The photosensitive drum 18 on which the electrostatic latent image has been formed is brought into contact with or proximity to a developing roller 17, whereby the electrostatic latent image is visualized as an image by the toner selectively adhering to the surface of the photosensitive drum in conformity with the electrostatic state thereof. The reference numeral 22 denotes a cassette containing transferring materials 29 therein. A transferring material fed from the cassette 22 by a feeding roller is conveyed between the photosensitive drum 18 and a transferring device 19 in the image forming portion by a conveying belt 20 for holding and conveying the transferring material. At this time, the toner image on the photosensitive drum 18 developed in the above-described developing process is transferred to the transferring material 29 by a transferring device 19. The image is passed through the image forming portions of four colors in succession, whereby developers of four colors are multiple-transferred.
Any residual toner on the photosensitive drum 18 which has not been transferred in this transferring process is removed and collected by a cleaning device 15 comprising a cleaning blade or the like. The reference numeral 23 designates a fixing device. The fixing device 23 is generally comprised of a plurality of rollers facing with each other, and has a heating portion such as a heater inside or outside the roller. Also, the fixing device 23 is provided with a temperature detector near the rollers, and is controlled so as to assume a predetermined temperature by monitoring temperature by a CPU or the like and controlling the heating amount of the heater. In the above-described transferring process, the transferring material 29 to which the toner has been transferred is heated and pressurized by the fixing device 23 and the toner image thereon is melted and fixed. Thereafter, the fixed transferring material 29 is conveyed through a discharging mechanism and is discharged from the image forming apparatus and thus, printing is completed.
In such an image forming apparatus, the above-described developing device 14 containing the toner is an interchangeable unit which must on occasion be interchanged due to the consumption of the toner. Such an interchangeable unit is interchanged by the user when the remaining amount of toner has been detected and the user has been informed of the detection result, or simply that it is time to exchange the unit because the toner is running low. The detection of the remaining amount of toner should more desirably be reported to the user before the toner becomes exhausted and printing becomes impossible than before the exhaustion of the toner is reported, so that the user can be prepared for the interchange of the interchangeable unit. Further, ideally, if the used amount of expendibles is always reported, the user can know precisely not only when it is time for interchange but also the used state of expendibles, and for example, this approach provides the user with information for judging whether the remaining expendibles are sufficient when a great deal of documents are to be printed. As described above, it is desirable that the used state of the interchangeable unit can be understood precisely.
However, the interchangeable unit like an article of consumption is a unit construction discrete from the main body of the image forming apparatus, and for example, when a developing device 14 used in other image forming apparatus is mounted on a discrete image forming apparatus, it is difficult to judge to what degree the developing device 14 has been used. So, a nonvolatile memory is carried on an interchangeable unit and the used amount of the interchangeable unit is cumulatively recorded in this nonvolatile memory, whereby even between different image forming apparatuses, the information of the interchangeable unit in the nonvolatile memory can be read out to thereby grasp the state of the interchangeable unit correctly and report it accurately to the user.
On the other hand, in the conventional system, there is the technique of mounting a nonvolatile memory such as EEPROM on an interchangeable unit, and connecting it to the main body of an image forming apparatus by a connector during the mounting of the interchangeable unit to thereby realize the interchange. When a nonvolatile memory is to be carried on an interchangeable unit, it is often the case that not an ordinary connector for a harness, but a drawer connector with a fitting member easily inserted and drawn out during the mounting and dismounting thereof is used. At the fitting portion, it is arranged, a guide member for absorbing the positional deviation due to the tolerance between the interchangeable unit and the main body of the apparatus during the mounting or dismounting of the interchangeable unit. The drawer connector is higher in cost than the ordinary connector for a harness.
Also, the nonvolatile memory carrying system by this drawer connector is of the contact type and therefore, bad contact may be caused, for example, by toner dust in the main body of the apparatus or dust entering from the outside, and there is a problem in the reliability of a connector contact, and this leads to the limitation that during the insertion and drawing-out of the connector, the contact need be formed by a self-cleaned slidable contact.
From such a point of view, there has been desired a nonvolatile memory system by the non-contact between the main body of the apparatus and the nonvolatile memory. So, in recent years, there has been devised a memory system capable of effecting non-contact communication which uses a nonvolatile-memory such as an FeROM or an FeRAM. This system is a system which is comprised of a transmitting circuit and a receiving circuit and in which generally from the transmitting circuit, data is superimposed on a carrier wave called a carrier and the electric power of the nonvolatile memory is supplied by the carrier and also the data is transmitted and received. The transmitting circuit is comprised of an antenna, and the nonvolatile memory side is also comprised of an antenna. The transmitting side antenna of the main body of the apparatus is driven by the above-mentioned carrier, and the antenna of the interchangeable unit side memory unit opposed thereto in non-contact is electromagnetically induced by an electromagnetic wave, whereby electric power is supplied to the memory unit. In this system, the problem regarding the reliability of the connector contact which has been the drawback of the nonvolatile memory carrying system of the contact type can be avoided.
FIG. 15 of the accompanying drawings is a circuit diagram of a communication part 600 in an image forming apparatus of the conventional type.
The communication part 600 is a circuit necessary for the communication of a memory of one channel.
A communication IC 105 effects communication with a memory unit 101 on the basis of information designated from a CPU or a logic IC, not shown. Also, the communication IC 105 superimposes the address, command and data of the memory unit designated by the CPU or the logic IC upon a carrier for supplying electric power to the memory unit 101 containing a nonvolatile memory therein, and produces a transmission signal.
The transmission signal is amplified into a transmission signal having an amplitude of several tens of volts by an amplification circuit 104, and drives an antenna portion 102 through a coupling capacitor 110 and generates an electromagnetic wave to thereby supply electric power to the memory unit 101 and also transmits the superimposed data.
The inductor of the antenna portion constitutes a tuning capacitor 108 and a resonance circuit having the carrier of the signal as a resonance frequency. The memory unit returns a reception signal on the basis of the transmitted data. The reception signal is received from the antenna portion 102 by a receiving circuit 113 through a coupling capacitor 111.
Like the inductor of the transmitting portion, the inductor of the receiving portion constitutes a tuning capacitor 109 and a resonance circuit. The communication IC 105 takes out the received data from the reception signal via the receiving circuit 113, and the CPU or the logic IC, not shown, reads it out. By such a system, there is constructed the conventional system in which reading and writing can be done in non-contact with the nonvolatile memory of the interchangeable unit.
However, the communication system of this radio frequency memory requires a communication IC. This communication IC is a communication IC exclusively for the radio frequency memory and therefore, its drawback is that its cost is high. Also, this non-contact type memory communication system is comprised of a transmitting circuit and a receiving circuit, as described above and therefore, the number of the parts of the electric circuits is great, and comparing the costs of only the communication circuits, this system is higher in cost than the contact type memory communication system using EEPROM. However, if the transmitting circuit and the receiving circuit are combined into a common circuit, it will be necessary to communicate with a faraway memory, and it will be necessary to transmit a strong electromagnetic wave from the antenna. However, the outputs by electromagnetic waves are regulated by law, and it is not desirable to make the output great. Also, in order not to output an unnecessary radiation wave, it is necessary to construct the transmitting portion of the main body of the apparatus and the nonvolatile memory unit at a short distance, and communicate by a feeble electromagnetic wave.
Also, when as described above, the nonvolatile memory is mounted in the interchangeable unit of the color image forming apparatus of the tandem type, four sets of drawer connectors are necessary in the contact type nonvolatile memory system and the cost becomes high, and in addition, this is not preferable from the viewpoint of the reliability of the contact of the connector. Also, in the radio frequency type nonvolatile memory system, four communication IC""s are necessary and moreover, four transmitting circuits and four receiving circuits are also necessary, and there cannot be provide an image forming apparatus of low cost. Also, when four sets of transmitting circuits and receiving circuits are constructed, the communication circuit board becomes bulky and a space therefor is necessary in the main body of the apparatus, and this has been difficult to realize. To observe the Wireless Telegraphy Act and minimize the unnecessary radiation waves, a method of suppressing the irregularity of the communication output of the transmitting circuit is necessary.
Further, in the above-described example of the prior art, among the plurality of communication circuits and among the plurality of transmitting and receiving circuits, the irregularity of the output electric power exists due to the manufacturing irregularity of elements constituting the circuits and the pattern irregularity of the board and therefore, to minimize the unnecessary radiation waves in connection with the Wireless Telegraphy Act, there is the problem that it is necessary to suppress the irregularity of the communication output of the transmitting circuit.
The present invention has been made in view of the above-noted points, and an object thereof is to provide an image forming apparatus, a communication controlling method and a storage medium in which a nonvolatile memory can be carried on each of a plurality of interchangeable units mounted on the image forming apparatus to thereby improve usability and yet improve reliability at a low cost.
It is also an object of the present invention to provide an image forming apparatus of the tandem type in which a nonvolatile memory is carried on each of a plurality of interchangeable units and a non-contact memory system unrelated to the reliability of contact of a connector can be realized at a low cost.
To achieve the above objects, the present invention provides an image forming apparatus on which a plurality of interchangeable units each provided with a nonvolatile memory are detachably mountable, characterized by changeover means for changing over a communication signal based on the radio frequency communication by an electromagnetic wave with the nonvolatile memory of each of the interchangeable units to a different communication circuit, and communication means for controlling the changeover means to thereby effect the communication with the nonvolatile memory of each of the interchangeable units.
Preferably, the interchangeable units may be units interchangeable due to the life or consumption of a developing container or the like in which a developer is contained.
Preferably, the communication means may have a plurality of amplifying means for amplifying a plurality of communication signals changed over to the different communication circuit by the changeover means.
Preferably, the communication means may have a plurality of transmitting and receiving means for effecting the transmission and reception of a signal with the nonvolatile memory of each of the interchangeable units, and second changeover means for changing over a reception signal received by each of the transmitting and receiving means.
Preferably, each of the changeover means and the second changeover means may be comprised of an analog switch.
Also, the communication controlling method according to the present invention is a communication controlling method applied to an image forming apparatus on which a plurality of interchangeable units each provided with a nonvolatile memory are detachably mountable, the method having the changing-over step of changing over a communication signal based on the radio frequency type communication by an electromagnetic wave between the main body of the image forming apparatus and the nonvolatile memory of each of the interchangeable units to a different communication circuit, and the communicating step of controlling the changing-over step to thereby effect the communication between the main body of the image forming apparatus and the nonvolatile memory of each of the interchangeable units.
Preferably, the interchangeable units may be units interchangeable due to the life or consumption of a developing container or the like in which a developer is contained.
Preferably, the communicating step may have a plurality of amplifying steps of amplifying a plurality of communication signals changed over to the different communication circuit by the changing-over step.
Preferably, the communicating step may have a plurality of transmitting and receiving steps of effecting the transmission and reception of a signal with the nonvolatile memory of each of the interchangeable units, and a second changing-over step of changing over a reception signal received by each of the transmitting and receiving steps.
Preferably, at the changing-over step and the second changing-over step, the changing-over operation is performed by an analog switch.
According to the present invention, a radio frequency memory system in which a nonvolatile memory is carried on each of a plurality of interchangeable units detachably mountable on an image forming apparatus and which is unrelated to the reliability of contact of a connector can be realized at a low cost. Further, communication means (communication IC""s) which have been the drawback of the radio frequency type can be made common to thereby realize a low cost, and further, the transmitting and receiving circuits can be partly made common to thereby realize space saving and a low cost. By effecting communication with a plurality of volatile memories by a communication means (communication IC), if the number of the interchangeable units is four, the communication means (communication IC) can be realized at a quarter cost. Further, by having a plurality of communication circuits, for a plurality of transmission outputs, each of them can be adjusted to a necessary sufficient output. By the system of the present invention an image forming apparatus effective for the observation of the regulation by the Wireless Telegraphy Act and the suppression of the unnecessary radiation waves can be designed. Also the changeover means and the second changeover means (analog switchers) are constructed on this side of the receiving circuit, whereby an entirely common circuit can be used as the receiving circuits, and it becomes possible to equip the entire communication circuit with space saving. By the present invention, it becomes possible to provide a system in which a nonvolatile memory can be carried on each of a plurality of interchangeable units detachably mountable on an image forming apparatus to thereby improve the usability thereof and which is low in cost and high in reliability.
According to the present invention, it becomes possible to provide a system in which a communication controlling method is executed by an image forming apparatus, whereby as described above, a nonvolatile memory can be carried on each of a plurality of interchangeable units detachably mounted on the image bearing apparatus to thereby improve the usability of the apparatus and yet which is low in cost and high in reliability.
Also, in another image forming apparatus according to the present invention, communication means provided in the image forming apparatus has an amplifying means provided for each signal controlling means for controlling a communication signal, switch means for selecting one of a plurality of communication circuits after the amplifying means has amplified the communication signal, and amplitude adjusting means for attenuating the amplitude of the communication signal passed through the switch means, and communicates with a plurality of nonvolatile memories by changing over the switching means.
According to the present invention, in an image forming apparatus of the tandem type, there is achieved the effect that a radio frequency memory system in which a nonvolatile memory is carried on each of a plurality of interchangeable units and which is unrelated to the reliability of contact of a connector can be realized at a low cost.
Also, the communication IC""s which have been the drawback of the radio frequency type are made common and therefore, a low cost can be realized and moreover, the transmitting and receiving circuits are partly made common and therefore, space saving and a low cost are realized. A plurality of nonvolatile memory communications are effected by a communication IC, whereby if the number of interchangeable units is four, a quarter communication IC cost can be realized, and the simplification and reduced cost of surrounding circuits such as amplification circuits can be realized.
Further, in the present invention, by having an amplitude adjusting circuit for each channel, for a plurality of transmission outputs, it is possible to adjust each of them to a necessary sufficient output. By this system, there is achieved the effect that an image forming apparatus effective for the observation of the regulation by the Wireless Telegraphy Act and the suppression of the unnecessary radiation waves can be designed.
According to the present embodiment, there is achieved the effect that there is provided a system which enables a nonvolatile memory to be carried on each of a plurality of interchangeable units to thereby improve the usability of the system and moreover, is low in cost and high in reliability.
These and other objects and advantages of the invention may be readily ascertained by referring to the following description and accompanying drawings.